Dear Mariella

The dilemma: A year ago, with my 30th birthday looming and having just bought a house with my boyfriend of five years, I broke all my morals and had an affair. I fell head over heels and immediately ended my relationship, as I knew I could not carry on with my partner, having developed feelings for another man. We've since set up home together and, apart from some teething problems, I am very happy. However, I have suddenly been hit by strong feelings of guilt about my ex. I feel I treated him terribly by leaving him suddenly and that he did not deserve it. But it's true our sex life had died a long time before and we had become more like brother and sister. As well as guilt, I feel sorrow at having lost this close friend in my life. The strangest part is that this guilt gets worse with time. Is this because I am coming out of the honeymoon period with my new relationship and the reality of how much I must have hurt my ex has become clear to me? I feel the need to make peace with him because it will ease my conscience, instead of letting him move on with his life. I'm also scared these negative feelings will begin to affect my current relationship with a man I want to build a future with. How can I clear my conscience without opening old wounds and perhaps creating new ones?

You can't, but that doesn't mean you shouldn't. A compulsion to clear one's conscience isn't some insignificant desire, like a mid-afternoon craving for a Bounty bar. It's an enormous commitment that will require a degree of effort and more than a little discomfort, not just for your ex but also for you. You seem to suggest that it's like wiping a blackboard or erasing a drawing, as though your conscience is something that, with a little bit of reassurance from the injured party, can be reborn as virginal territory. Either you have a particularly underdeveloped connection to past deeds or you're something of an optimist.

There's a lot of stuff going on here, isn't there? I wonder how much of it has to do with either of the men in your life and how much is just about you. For example, your need now to refocus on your old relationship just as the new one is becoming a permanent fixture suggests you may be a bit of a stargazer - always thinking that what lies above, behind or ahead is more valuable than what you've got. It's suggested by your decision to embark on an affair at just the point that you'd achieved some sort of stability last time around. Now you've had your cake, eaten it and are ravenous all over again. It's a pattern of behaviour that will make you seriously unhappy in your life if you don't address it now. Your letter doesn't give me enough information to know for sure that this is your modus operandi, but it certainly hints that it might be.

If you detect a sliver of truth in what I'm saying, do please make an effort to address it. It may not be your conscience that needs attention at all, but your greedy eye for what you haven't got. The unhappiest people I've ever met are the ones who never recognise happiness when they are enjoying it. It's always a state of being that in their blinkered view is either just around the corner or a distant memory. So do make sure that you learn to recognise happiness, and not just eternally yearn for it.

Going back to your ex, can we presume that you have destroyed his life without fear of contradiction? You don't mention how he (or indeed your current partner) is feeling, so I've no idea whether your decision to leave him ruined his life or improved it. If you were living together like brother and sister, you may have done him a favour. For all we know, he's now having the time of his life with a busty, leggy nymphomaniac and hasn't given you a second thought. That may sound spiteful on my part, but I'm merely flagging it up as a possibility. Would that ease your conscience? Or get you wondering whether you had backed the wrong horse?

You go to quite an effort to make clear your affair lasted only as long as was required for you to know you wanted to move on from your ex-boyfriend. That doesn't give you a spot on the moral high ground, you were just more speedily decisive than most. In fact, it leaves me with this nagging sensation that you earnestly want everyone to be happy so long as it doesn't require any sacrifice on your part. Reconnecting with your ex will either cause him or your new partner pain. As I said, it doesn't mean that you shouldn't do it - you just need to be realistic about the fallout. If he's moved on and is reasonably content, you have a chance of reigniting your friendship; if he hasn't, your appearance will no doubt briefly offer him false hope before he crashes back to earth with the realisation that you're not on your way back.

The only certainty is that the choices you make will continue to affect other people's lives. That's why I'm all for you considering your options, but not just because you're missing out elsewhere.